[PATCH v8 0/4] ACPI: parse the SPCR table

Timur Tabi timur at codeaurora.org
Fri Jun 17 16:24:57 PDT 2016


On Fri, May 20, 2016 at 8:03 AM, Aleksey Makarov
<aleksey.makarov at linaro.org> wrote:
> 'ARM Server Base Boot Requirements' [1] mentions SPCR (Serial Port Console
> Redirection Table) [2] as a mandatory ACPI table that specifies the
> configuration of serial console.
>
> Move "earlycon" early_param handling to earlycon.c to parse this option once
>
> Parse SPCR table, setup earlycon and register specified console.
>
> Enable parsing this table on ARM64.  Earlycon should be set up as early as
> possible.  ACPI boot tables are mapped in
> arch/arm64/kernel/acpi.c:acpi_boot_table_init() called from setup_arch() and
> that's where we parse spcr.  So it has to be opted-in per-arch. When
> ACPI_SPCR_TABLE is defined initialization of DT earlycon is deferred until the
> DT/ACPI decision is done.
>
> Implement console_match() for pl011.
>
> Based on the work by Leif Lindholm [3]
> Thanks to Peter Hurley for explaining how this should work.
>
> Should be applied to next-20160520
> Tested on QEMU and ThunderX.
> SPCR support is included in QEMU's ARM64 mach-virt since 2.4 release.
>
> v8:
> - rebase to next-20160520
> - remove the patch "ACPICA: Headers: Add new constants for the DBG2 ACPI table"
>   as it have got to linux-next
> - add Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>, Reviewed-by:
>   Peter Hurley <peter at hurleysoftware.com> (but see below)
> - fix the patch "serial: pl011: add console matching function".  The patch by
>   Christopher Covington [4] specifies that SBSA uart does 32-bit access to
>   registers and this breaks the match function.  In this series the function
>   was changed to match when SPCR specifies both mmio32 and mmio access.
>   I removed Acked-by: Greg from this patch because of these changes.

All four patches:

Tested-by: Timur Tabi <timur at codeaurora.org>

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